Improvement in boilers for steam fire-engines



M. R CLAPP..

Boiler for Steam Fire-Engine.

Patented June .18, |878.

UNITED STATES PATENT OEEIoE.

MiETrLLow E. cLAPP, or EUDsoN, NEW-Yoan.`

IMPROVEMENT IN -BOILERS FOR STEAM 'FIRE-ENGINES.

Specification forming part of Letters Patent No. 204,885, dated J une 18, 1878; application filed May 11, 1878.

To all whom it may concern:

Be it known that I, MIRTiLLow B. GLAPP, of Hudson, in the county of Columbia and State of New York, have invented an Improved Boiler for Steam Fire-Engines, of which the following is a speciiication:

Figure l is a vertical central section of my improved boiler for steam nre-engines. Fig. 2 is a horizontal section ofthe same on the line c c, Fig. l.

Similar letters of reference indicate corresponding parts in all the gures.

This invention relates to steam-boilers ofthe kind used in steam lire-engines, which boilers are more exposed to the danger of corrosion at certain particular places than other boilers, and which are required to be so constructed that steam may be very rapidly created therein. The tire-engines are in actual use only during very limited periods, and yet they must .be kept ready for immediate use during all the long periods of rest. During this time the water in the boiler stands at a certain height, substantially invariable, and at the Water-line; therefore, the boilers are very lia-ble to corrosion.

Now, my Vinvention consists, rst, in the use of a water-drum placed into an annular upright boiler and made to communicate with the water-space of the boiler proper at a line which will allow a very limited quantity of water to protect the bottom of said drum, so that steam may be rapidly raised in the latter, as hereinafter more fully described.

The invention also consists in other details of improvement, hereinafter pointed out.

In the accompanying drawing, the letter A indicates the outer shell of a cylindrical upright steam-boiler, which, however, may also,

` if desired, be of other suitable form. B is the inner wall of this boiler. Between the walls A and B an' annular water and steam chamber, a, is formed. C is a water and steam drum, of less diameter than the inner wall B, and is placed into the boiler above the lirechamber thereof, and put in communication with the space a by one or more lower waterpipes, b, and one or more upper steam-pipes, d, as shown in Fig. l. Between the outer periphery of the drum C and the wall B there is an annular smoke-passage, e, as shown.

Smoke-lines f may, if desired, be made to extend vertically through the drum C, asindicated, said iiues being opened at both 'ends for permitting the escape of the products of combustion; but instead of said iues f f upright bolts may be used to hold the top and bottom plates of the drum at the proper distance apart. The tubes, however, are preferable, and, when used, should be made of copper, their upper ends projecting above the drum, as shown, said upper ends being ex-` panded to receive iron rings g, whereby they are held expanded and securely locked to the upper part of the drum. These ilues, when made of copper, will not be injuriously affected by the water in the drum.

From the bottom i of the drum project downwardly a series of water-tubes, h h, which eX- pose a large heating-surface to the tire, and which I do not claim to have invented. rIhe pipe b, which establishes Water communication between the interior ofthe drum and the annular chamber a, is at but a short distance above the bottom i of the drum, as clearly shown in Fig. l.

When the engine is at rest, I propose to have in the drum C just about enough Water as to ll it to the pipe b, thus leaving a thin sheet of water on the bottom i of the drum, sufficient, however, to protect said 'bottom against the injurious et't'ects of lire. YAs soon as the lire is started ebullition of the water will cause it to vrise in the drum and to more or less escape into the space a, in which space it is unnecessary to have the water at the commencement of the fire at the same height as in the drum. Thus the volume of water in the drum will still more be reduced within the drum by escape through the pipe b into the space a, and a very small fire will consequently suffice to create steam rapidly within the drum sufficient for the purpose of starting the engine.

I prefer to have a series of pipes, b b, leading into the drum C, and also a series of steampipes, l d, at the upper part thereof, as Ihave found that water will not be level within the drum if there is but a single outlet for water or steam. V

For further strengthening the drum and insuring. its safe position Within the boiler, I bulge the wall B inward at certain parts, so as to cause it to reach the drum, as shown at m in Fig. l. These bulging portions 'm m are, by bolts n n, secured to the drum, and serve to fasten the same properly in place and to hold it during the operation of the boiler; but instead of having these bulges m m on the inner Wall B they may been the drum and extend against the inner Wall with substan tially the saine effect.

I claiml. In a steam fire-engine boiler, the combination of the drum C, carrying the watertubes h, with the connecting-pipes b and d, and Water and steam reservoir a, all arranged so that a smokespace, e, is left between the drum and the wall B of the space a, substantially as herein shown and described.

the smoke-passage e, substantially asshown` and described.

MIRTILLOW R. CLAPP.

Witnesses:

A. J. GIFFORD, S. W. TOBEY, Jr. 

